Cormus Knolle, f Raíz tuberosa An underground storage organ of solid material, being a swollen part of a stem, and not having scales as a true bulb. Often refered to as bulb as in crocus bulb or gladiolus bulb.

A crocus comes from a corm. Corms are sometimes called bulbs, but they are not true bulbs, nor are they roots. An onion, which is a true bulb, has layers in its underground stem; a crocus is also an underground stem, but it is solid. Corms, like bulbs, will produce roots only from their bottom.

n. (L. cormus; Gr. kormus, the trunk of a tree with the boughs lopped off) an enlarged solid subterranean stem, often rounded in shape but of no distinct characteristic shape or size in some species, filled with nutrients, composed of two or more internodes and covered externally by a few thin membranous scales or cataphyllary leaves.

A corm is a short, vertical, swollen underground stem of a plant (usually one of the monocots) that serves as a storage organ to enable the plant to survive winter or other adverse conditions such as summer drought and heat (estivation). A corm consists of one or more internodes with at least one growing point, and is typically surrounded by protective skins or tunics. Inside, a corm is mostly starch-containing parenchyma cells.